Just a late reply here...
The attitude file does control the attitudes of the various factions towards not only eachother but the player as well. Just carefully look at my quick howto (post #7) and the last column for each faction is for the player. Just simply change that column for each faction you want to edit and make it however you wish according to the values that I described in my post...you should easily be able to make various factions hate, like or be neutral towards jimmy.
I will note tho that if you already completed the game and are at the endless summer stage....no amount of editing this file will change anything since it is overridden in endless summer. I will post soon a guide on how to override that.
